Condensed Consolidated Balance Sheets - USD ($) $ in Thousands	Mar. 31, 2016	Dec. 31, 2015
Current assets:
Cash and cash equivalents	$ 13,095	$ 29,268
Inventory	475	482
Prepaid expenses and other current assets	1,036	1,244
Total current assets	14,606	30,994
Property and equipment, net of accumulated depreciation of $1,321 and $1,242, respectively	1,576	1,582
Intangible assets, net of accumulated amortization of $2,342 and $2,204, respectively	3,998	4,136
Other assets	30	0
Total assets	20,210	36,712
Current liabilities:
Accounts payable	893	499
Related party payable	1,078	10,720
Accrued expenses	636	1,779
Deferred revenue	462	457
Warrant liability, current	282	1,910
Total current liabilities	3,351	15,365
Warrant liability, long term	2,736	6,365
Deferred rent	782	779
Total liabilities	6,869	22,509
Stockholders’ equity:
Preferred stock, $0.001 par value; 5,000,000 shares authorized; no shares outstanding	0	0
Common stock, $0.001 par value; 100,000,000 shares authorized; 43,898,785 shares issued and outstanding	44	44
Additional paid-in capital	161,975	161,330
Accumulated deficit	(148,678)	(147,171)
Total stockholders’ equity	13,341	14,203
Total liabilities and stockholders’ equity	$ 20,210	$ 36,712